 # 4 Energy – Part A “Units”

### Syllabus Aims…

4.1 use the following units: kilogram (kg), joule (J), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s), watt (W).

### Resources…

Kilogram (kg): the SI unit of mass, equivalent to the international standard kept at Sèvres near Paris (approximately 2.205 lb).

Joule (J): the SI unit of work or energy, equal to the work done by a force of one newton when its point of application moves one metre in the direction of action of the force.

Speed: the rate at which someone or something moves or operates or is able to move or operate.

Acceleration (m/s/s OR Nkg-1 OR ms-2) vehicle’s capacity to gain speed.

Metre (m): the fundamental unit of length in the metric system, equal to 100 centimetres or approximately 39.37 inches.

Newton (N): the SI unit of force. It is equal to the force that would give a mass of one kilogram an acceleration of one metre per second per second.

Watt (W): the SI unit of power, equivalent to one joule per second, corresponding to the rate of consumption of energy in an electric circuit where the potential difference is one volt and the current one ampere.

## 4 Energy – Part B “Energy Transfers”

Syllabus Aims Year 9….
4.2 describe energy transfers involving energy stores:

energy stores:
chemical
kinetic
gravitational
elastic, thermal
magnetic
electrostatic
nuclear

energy transfers:

mechanically
electrically
by heating

4.3 use the principle of conservation of energy
4.4 know and use the relationship:
efficiency = (useful energy output/total energy input) x 100%

4.5 describe a variety of everyday and scientific devices and situations, explaining transfer of the input …

## 4 Energy – Part C “Work Energy and Power”

Syllabus Aims…
4.11 know and use the relationship between work, force and distance moved in the direction of the force:
work done = force × distance moved
W = F × d
4.12 know that work done is equal to energy transferred.
4.13 know and use the relationship:
gravitational potential energy =  mass × g × height
GPE = m × g …

## 4 Energy – Part D “Energy and Human Influences”

Syllabus Aims…
4.18P describe the energy transfers involved in generating electricity using:

wind
water
geothermal resources
solar heating systems
solar cells
fossil fuels
nuclear power

4.19P describe the advantages and disadvantages of methods of large-scale electricity production from various renewable and non-renewable resources.

Energy

Energy store

Uses

Power output

Impact on environment

Fossil fuels (oil, coal and natural gases)

Chemical

Transport, heating, electricity generation

High

Releases CO2 (causes global warming)

Nuclear fuels

Nuclear

Electricity generation

Very high